PHP MYSQL Query Algorithm Help

I'm a designing a website that orders results on its votes and ages.

I found the reddit algorithm and I think that is the best to use. However, I do not know how to implement this into php. I have searched google on how to do this but I cannot find any results. I don't know if it is just mean because I do not know exactly what I should be searching.

I know basic PHP however, is there a way of doing this in a simple way.

Is it possible to do it like this:

"SELECT * FROM table ORDER BY algorithm_here DES开发者_运维技巧C";

The reddit algorithm is as follows:

Log10(Z) + ((Y*Ts)/45000) = rank

A = time posted

B = 00:00:001 am 1/1/2010

U = Up votes

D = Down votes



Ts = A-B


X = U-D


Y =

1 if x>0

0 if x=0

-1 if x<0


z = max(abs(x),1)

Well if its me, i will write an UDF in MySQL called may be reddit_algo or something and use it like

SELECT
    *,
    reddit_algo() as rating
FROM
    `table`
ORDER BY
    `rating`
LIMIT 30;

If you want the stored function then here is it. i just wrote it fast and didnt get time to check it fully. I definitely hope this works. :)

DELIMITER &&

DROP FUNCTION IF EXISTS reddit_rank &&

CREATE FUNCTION reddit_rank(time_posted TIMESTAMP, up_votes INT, down_votes INT) RETURNS NUMERIC(10,6)
    DETERMINISTIC

BEGIN
    DECLARE start_time TIMESTAMP;
    DECLARE Ts INT;
    DECLARE vote_diff INT;
    DECLARE y TINYINT;
    DECLARE z1 INT;
    DECLARE z INT;
    DECLARE rank NUMERIC(10,6);

    SET start_time = "2010-01-01 00:00:01";
    SET Ts = TIMESTAMPDIFF(SECOND,start_time, time_posted);

    SET vote_diff = up_votes - down_votes;

    IF vote_diff > 0 THEN
        SET y = 1;
    ELSEIF vote_diff < 0 THEN
        SET y = -1;
    ELSE
        SET y = 0;
    END IF;

    SET z1 = ABS(vote_diff);

    IF z1 >= 1 THEN
        SET z = z1;
    ELSE    
        SET z = 1;
    END IF; 

    SET rank = LOG10(z) + ( (y*Ts)/45000 ); 

   RETURN(rank);

END &&

DELIMITER ;

SELECT
    *,
    reddit_rank(`time_added`, `up_votes`, `down_votes`) as rank
FROM
    `table`
ORDER BY
    rank;

Hope this helps. :) .. if u have any doughts on how to use a stored function and all try google searching.

Then again. I still want to say it again, it is not adivisable to use a stored function or any of such thing if you have a large database. So i strongly recommend to write a UDF. If you don't know how to do it; then for the time being adjust with this function and when the load increases and you start making lots of revenue get someone to write a UDF function for you. ;) ..